1.\" -*- nroff -*- 2.\" 3.\" Copyright (c) 1996 Doug Rabson 4.\" 5.\" All rights reserved. 6.\" 7.\" This program is free software. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 19.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 22.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28.\" 29.\" $Id: VOP_LINK.9,v 1.1 1997/03/03 18:00:23 dfr Exp $ 30.\" 31.Dd July 24, 1996 32.Os 33.Dt VOP_LINK 9 34.Sh NAME 35.Nm VOP_LINK 36.Nd create a new name for a file 37.Sh SYNOPSIS 38.Fd #include <sys/vnode.h> 39.Ft int 40.Fn VOP_LINK "struct vnode *dvp" "struct vnode *vp" "struct componentname *cnp" 41.Sh DESCRIPTION 42This links a new name in the specified directory to an existing file. 43.Pp 44Its arguments are: 45.Bl -tag -width 8X 46.It Ar dvp 47the vnode of the directory 48.It At vp 49the vnode of the file to be linked 50.It Ar cnp 51pathname information about the file 52.El 53.Pp 54The directory vnode is unlocked and released on exit. 55.Sh LOCKS 56The directory, 57.Fa dvp 58should be locked on entry and will be unlocked and released on exit. 59The file 60.Fa vp 61should not be locked. 62.Sh RETURN VALUES 63Zero is returned if the file was linked successfully, otherwise an 64error is returned. 65.Sh PSEUDOCODE 66.Bd -literal 67int 68vop_link(struct vnode *dvp, struct vnode *vp, struct componentname *cnp) 69{ 70 int error = 0; 71 72 if (vp->v_mount != dvp->v_mount) { 73 VOP_ABORTOP(dvp, cnp); 74 error = EXDEV; 75 goto out2; 76 } 77 if (vp != dvp && (error = VOP_LOCK(vp))) { 78 VOP_ABORTOP(dvp, cnp); 79 goto out2; 80 } 81 82 if (vp would have too many links) { 83 VOP_ABORTOP(dvp, cnp); 84 error = EMLINK; 85 goto out1; 86 } 87 88 if (vp is immutable) { 89 VOP_ABORTOP(dvp, cnp); 90 error = EPERM; 91 goto out1; 92 } 93 94 /* 95 * Increment link count of vp and write back the on-disc version of it. 96 */ 97 ...; 98 99 if (!error) { 100 /* 101 * Add the new name to the directory. 102 */ 103 ...; 104 } 105 106 free(cnp->cn_pnbuf, M_NAMEI); 107out1: 108 if (vp != dvp) 109 VOP_UNLOCK(vp); 110out2: 111 vput(dvp); 112 113 return error; 114} 115.Ed 116.Sh ERRORS 117.Bl -tag -width Er 118.It Bq Er EPERM 119the file is immutable 120.El 121.Sh SEE ALSO 122.Xr vnode 9 123.Sh AUTHORS 124This man page was written by Doug Rabson. 125